Paradoxical chest/abdominal movements

Diagram A shows normal inhalation and Diagram B shows paradoxical respiration with bulging of the abdominal cavity and sternal recession with inspiration.

Fig 1

Breath sounds and abnormal noises

Obstruction of the upper airway leads to turbulent flow which generates a noise similar to snoring. Complete airway obstruction leads to an absence of breath sounds. Obstruction of the lower airway can cause stridor.